Transmission-line clamp-and-connector



I. S. BLONDER TRANSMISSION-LINE CLAMP-AND-CONNECTOR March 26, 1963 Filed Sept. 18, 1961 INVENTOR. 13/946 6: 8(0/1/056 BY fin M m 4770/8/VEV3 United States Patent Ofifice 3,083,349 Patented Mar. 26, 1963 3 083,349 TRANSNHSSION-LINE CLAMP-AND-CONNECTSR Isaac S. Blonder, West Grange, N.J., assignor to Blonder Tongue Electronics, Newark, N.J., a corporation of New Jersey Fiied Sept. 18, 1961, Ser. No. 138,899 7 Claims. (Cl. 339-98) The present invention relates to transmission-line clamps and connectors and, more particularly, though not exclusively, to clamps and connectors suitable for operation with two-conductor transmission lines, such as those used in radio communication, and television, and the like.

Throughout the years, a large number of different types of transmission-line clamps and connectors have been proposed for use with different varieties of transmission lines employed in the electrical arts, including transmission lines for carrying received television broadcast or similar radio signals, such as coaxial or parallel-conductor transmission lines. Included in such proposals are the connectors and clamps disclosed in my prior United States Letters Patent No. 2,843,827, issued July 15, 1958, and in my copending application Serial Number 750,489, filed July 23, 1958, now Patent No. 3,016,510, for Electrical Clamp-And-Connector.

While the above connectors are satisfactory for many applications, there are cases, as where multiplicities of transmission lines must be rigidly held in place at junction-boxes or other outlet receptacles, where it is necessary to provide very strong clamping action for a plu rality of transmission lines while insuring common grounding or other common connection. Frequently, at such junction boxes or outlets, the lines may be subjected to sharp bands or flexing, which impost strict limitations upon the rigidity and strength of the clamping and the effectiveness of the grounding or other common-conductor connections.

An object of the present invention is to provide a new and improved clamp and connector that is particularly suited to the simultaneous clamping and electrical connection of conductors of a plurality of transmission lines, such as coaxial lines and the like, with not only an un usual degree of clamping action, but with the insurance of common electrical connection of, for example, the outer ground conductors of the coaxial lines or the like.

A further object is to provide a novel transmissionline clamp that also permits of ready variation in the degree of clamping pressure, if desired.

An additional object is to provide a new and improved transmission-line clamp and connector of more general utility, also.

Other and further objects will be explained hereinafter and will be more particularly pointed out in connection with the appended claims.

In one of its broadest aspects, the invention resides in the combination of a relatively fixed bracket substantially L-shaped in cross-section with the upward leg of the L provided with a first pair of downwa-rdlyextending notches spaced transversely a predetermined distance along the upright leg and serrated along the bottom of the notches; a relatively movable bridge-type clamp of substantially inverted U-shape in cross section having its opposite arms provided with alined further pairs of upwardly extending notches, the notches of each of the further pairs of notches being serrated along the top thereof and spaced transversely the said predetermined distance; alined apertures disposed in the neck of the inverted U-shaped clamp and in the lower leg of the L-shaped bracket provided with means for compressing the clamp and bracket with an arm of the clamp just inside the said upright leg; and the width of the clamp being less than that of the said lower bracket leg in order that, with a pair of insulation-covered two-cond-uctor transmission lines inserted through the first and further pairs of notches, the insulation-covered lines will become clamped against the lower bracket leg with the serrations of the notches penetrating different adjacent portions of the said insulation to contact one of the conductors of each of the transmission lines and to connect the same electrically to the clamp and bracket. Preferred constructional details are hereinafter set forth.

The invention will now be described in connection with the accompanying drawing, FIG. 1 of which is a perspec tive view illustrating a transmission-line clamp-and-connector arrangement constructed in accordance with a preferred embodiment of the invention, the parts being shown in unassembled relationship; and

FIG. 2 is a similar fragmentary view of the parts in assembled form.

A pair of coaxial transmission lines are shown at 1, each comprising an inner conductor 2, insulated from an outer braid sheath conductor 4, and insulation-covered externally at 6. In order simultaneously to provide very rigid clamping of this plurality of transmission lines, and at the same time to connect the outer sheath conductors to the clamp structure, which may be grounded,

a bracket 3 is provided. The bracket 3 is fixed, as with the aid of rivets 5 and the like, .to, for example, a cover plate 7 fora television-signal wall outlet or similar receptacle. The left-hand portion of the bracket 3 comprises an angle bracket that is substantially L-shaped in cross section, having an upright leg 3 and a flat lower leg 3". The upright leg 3 of the fixed bracket 3 is provided with a first pair of downwardly extending notches 14 spaced transversely a predetermined distance and serrated at 16 along the bottom thereof. From the forward or right-hand edge of the lower leg 3", there depends a downwardly inclined extension 9 for mounting an insulating plate -11 that may carry a pair of binding post terminals 13 to which the inner conductors 2 of the transmission lines 1 may be connected.

Cooperating with the L-shaped bracket 3 is a relatively movable bridge-type clamp of substantially inverted U-shape in cross-section having its opposite arms 10 and 10 provided with further upwardly extending notches 12, and 12', spaced transversely along the respective arms 10 and 10' the same predetermined distance that the notches 14 are spaced along the upper leg 3' of the L-shaped bracket 3. The notches 12 and 12' are also shown provided with serrations 18, 18', respectively, along the top thereof.

' The bridge-type clamp 10-10 is compressible with respect to the relatively fixed bracket 3'3" through the aid of screws 20 that pass through alined apertures 22 and 24 disposed respectively in the neck 10" of the U-shaped clamp 10-10 and in the lower leg 3" of the fixed bracket 33 pairs of notches 14, 12, 12'. This location gives a balanced compressing action, with the degree of tightening of the screws 20 controlling the degree of clamping.

When the transmission lines 1 are inserted through the notches .14 in the upright leg 3' of fixed bracket 3'3", FIG. 2, and through the alined pairs of notches 12 and 12' in the opposite arms 10 and 10 of the U-shaped clamp, and the screws 29 are tightened down thereupon, the serrations 16 at the bottom of the notches 14, will dig into the lower surface portions of the insulation 6 and effect multiple spaced contact with the out-er braid conductors 4, simultaneously mechanically staking the transmission line at that position. The arm 10 of the clamp will be forced down inside the upright leg 3 of the fixed bracket 3, to the right thereof in FIG. 2, and

, preferably on opposite sides of the 3 thus the serrations 18 in the notches 12 thereof will penetrate the upper surface portions of the insulation just to the right of and above the position of penetration of the serrations 16 of the notches :14. Not only does this construction establish multiple electrical connection with the braid outer conductors 4, but it stakes the transmission-line in the plane of the arm 16, disposed just to the right of the plane of the leg 3'. Still further stabilization of the staking and clamping is effected through the action of the serrations 18' in the upwardly extending notches 12' in the other arm of the bridge clamp, to the right of the arm 10, thereby providing symmetrical, stabilized clamping action with insurance of common electrical connection of the outer conductors 4 of the plurality of transmission lines. By constructing the width of the clamp 10, 10 to be less than that of the lower bracket leg 3", as shown, the insulation-covered lines 1 rest stably clamped against the lower bracket leg. All of the notches, moreover, are shown converging toward the serrations in order further to dig into and stake the insulation 6 in the desired positions as. the upper bridge clamp 10-.10' is compressed against the fixed bracket 3-3". The inner conductors may then be readily bent down into. engagement with the terminals 13, FIG. 2, for establishing the electrical terminal connections.

While the invention has been described in connection with the clamping of a pair of transmission lines 1, it is understood that more than the two transmission lines may, of course, be clamped, as with the aid of additional notches in the fixed bracket member 3-3" and the bridge clamp 10-:10. A single transmission-line clamping unit may also be provided in the same manner.

Further modifications will also suggest themselves to those skilled in the art and all such areconsidered to fall within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. A transmission-line clamp-and-connector having, in combination, a relatively fixed bracket substantially L-s haped in cross section with the upright leg of the L provided with a first pair of downwardly extending notches spaced transversely a predetermined distance along the upright leg and serrate-d along the bottom of the notches; a relatively movable bridge-type clamp of substantially inverted U-shape in cross section having its opposite arms provided with alined further pairs of upwardly extending notches, the notches of each of the further pairs of notches being serrated along the top thereof and spaced transversely the said predetermined distance; alined apertures disposed in the neck of the inverted U-s-haped clamp and in the lower leg of the L-shaped bracket provided with means for compressing the clamp and bracket with an arm of the clamp just inside the said upright bracket leg; and the width of the clamp being less than that of the said lower bracket leg in order that, with a pair of insulation-covered twoconductor transmission lines inserted through the first and further pairs of notches, the insualtion-covered lines will become clamped against the lower bracket leg with the serrations of the notches penetrating different adjacent portions of the said insulation to contact one of the conductors of the transmission lines and to connect the same electrically to the clamp and bracket.

2. A transmission-line clamp-and-connector as claimed in claim 1 and in which the sides of the notches converge toward the serrations thereof.

3. A transmission-line clamp-and-connector as claimed in claim 1 and in which the said apertures are disposed on opposite sides of the pairs of notches and the compressing means comprises screw means threaded through the alined apertures in the said neck of the clamp and the said lower bracket leg.

4. A transmission-line clamp-and-connector as claimed in claim 1 and in which the said lower bracket leg is provided with a downwardly inclined extension containing terminal means for establishing electrical connection with the other conductors of the transmission lines.

5. A transmission-line clamp-and-connector having, in combination, a relatively fixed bracket substantially L-shaped in cross section with the upright leg of the L provided with downwardly extending notch means serrated along the bottom thereof; a relatively movable bridge-type clamp of substantially inverted U-shape in cross section having its opposite arms provided with further upwardly extending notch means serrated along the top thereof; alined apertures disposed in the neck of the inverted U-shaped clamp and in the lower leg of the L-shaped bracket provided with means for compressing the clamp and bracket with an arm of the clamp just inside the said upright bracket leg; and the width of the clamp being less than that of the said lower bracket leg in order that, with an insulation-covered two-conductor transmission line inserted through the first and further notch means, the insulation-covered line will become clamped against the lower bracket leg with the serrations of the notch means penetrating different adjacent portions of the said insulation to contact one of the conductors of the transmission-line and to connect the same electrically to the clamp and bracket.

6. A transmission-line clamp-and-connector as claimed in claim 5 and in which the sides of the notch means converge toward the serrations thereof.

7. A transmission-line clamp-and-connector as claimed in claim 5 and in which the said lower bracket leg is provided with a downwardly inclined extension containing terminal means for establishing electrical connection with the other conductor of the transmission line.

No references cited. 

1. A TRANSMISSION-LINE CLAMP-AND-CONNECTOR HAVING, IN COMBINATION, A RELATIVELY FIXED BRACKET SUBSTANTIALLY L-SHAPED IN CROSS SECTION WITH THE UPRIGHT LEG OF THE L PROVIDED WITH A FIRST PAIR OF DOWNWARDLY EXTENDING NOTCHES SPACED TRANSVERSELY A PREDETERMINED DISTANCE ALONG THE UPRIGHT LEG AND SERRATED ALONG THE BOTTOM OF THE NOTCHES; A RELATIVELY MOVABLE BRIDGE-TYPE CLAMP OF SUBSTANTIALLY INVERTED U-SHAPE IN CROSS SECTION HAVING ITS OPPOSITE ARMS PROVIDED WITH ALINED FURTHER PAIRS OF UPWARDLY EXTENDING NOTCHES, THE NOTCHES OF EACH OF THE FURTHER PAIRS OF NOTCHES BEING SERRATED ALONG THE TOP THEREOF AND SPACED TRANSVERSELY THE SAID PREDETERMINED DISTANCE; ALINED APERTURES DISPOSED IN THE NECK OF THE INVERTED U-SHAPED CLAMP AND IN THE LOWER LEG OF THE L-SHAPED BRACKET PROVIDED WITH MEANS FOR COMPRESSING THE CLAMP AND BRACKET WITH AN ARM OF THE CLAMP JUST INSIDE THE SAID UPRIGHT BRACKET LEG; AND THE WIDTH OF THE CLAMP BEING LESS THAN THAT OF THE SAID LOWER BRACKET LEG IN ORDER THAT, WITH A PAIR OF INSULATION-COVERED TWOCONDUCTOR TRANSMISSION LINES INSERTED THROUGH THE FIRST AND FURTHER PAIRS OF NOTCHES, THE INSULATION-COVERED LINES WILL BECOME CLAMPED AGAINST THE LOWER BRACKET LEG WITH THE SERRATIONS OF THE NOTCHES PENETRATING DIFFERENT ADJACENT PORTIONS OF THE SAID INSULATION TO CONTACT ONE OF THE CONDUCTORS OF THE TRANSMISSION LINES AND TO CONNECT THE SAME ELECTRICALLY TO THE CLAMP AND BRACKET. 